1. Field of the Invention
This invention concerns antitheft devices and more particularly is concerned with locking fuel line shutoff valves designed to prevent unauthorized operation of the motor vehicle by providing a key-operated or locking valve shutting off the fuel supply to the vehicle engine.
2. Description of the Prior Art
Due to the emergence of the modern professional auto thief, the conventional ignition and door lock prevention of unauthorized operation of the vehicle has become too easily circumvented for effective antitheft protection. It is well known that the theft-to-order professional can enter a locked car and start the vehicle engine within a matter of minutes and indeed seconds in the usual situation. Thus, a need for supplemental arrangements to the ignition and door locks are seen by many as desirable particularly in high crime areas and for vehicles especially subject to theft. While no system can truly defeat the determined professional with unlimited time, generally if the efforts of the thief require more than just a few minutes, the theft will effectively be prevented since such professional will ordinarily not attempt to expend more than this matter of several minutes defeating whatever antitheft arrangements are encountered.
An example of one effort at preventing theft is the steering wheel locks now standard in automobiles. Such systems have not served to effectively deter the professional thief.
Another such system which has heretofore been proposed is described in U.S. Pat. No. 2,881,789 to Finazzo is the locking fuel line shutoff valve. Often such antitheft fuel shutoff arrangements include valves which are merely mounted beneath the hood of the automobile, although in the system involved in Finazzo, the fuel line is interrupted in approximate alignment with the front seat of the vehicle and the lock tumbler mechanism which operates the valve projects upwardly into the passenger compartment for convenient access thereto by the vehicle operator. While all such arrangements interpose one further obstacle to the would-be thief, these particular systems as implemented are easily bypassed by simply cutting the tubing leading into and out of the locking fuel line shutoff valve and effectively bypassing the valve and enabling the fuel to be supplied to the engine. This bypassing manuever can be carried out very quickly to thus allow substantial risk of theft notwithstanding its provision. Of course, any such antitheft arrangement or device should be desirably relatively simple and trouble-free and should not pose maintenance burdens to the owner and reduce significantly the reliability of operation of the vehicle since convenience factors loom large in the minds of most car owners.
Furthermore, since these devices are typically purchased by do-it-yourself mechanics, their installation should not be unduly complex and, even if put together by professionals, the time required for installation should very desirably be kept to a minimum to reduce the cost of installation of the device. Similarly, the cost of the device itself should be kept low in accordance with the market factors involved with such automotive consumer add-on devices.
Accordingly, it is an object of the present invention to provide an antitheft locking fuel shutoff device which greatly increases the difficulty encountered in defeating the device by a would-be thief or other unauthorized vehicle operator.
It is a further object of the present invention to provide an antitamper arrangement for such locking fuel shutoff valves which is relatively simple and fail-safe in operation.
It is yet another object of the present invention to provide such an antitamper device for locking fuel shutoff valves which is easily installed and reliable in operation and which may be manufactured at very low cost.